Internal-combustion engine



FIG. 1 is a front view of an internal-combustion engine.

FIG. 2 is a back view of the internal-combustion engine.

FIG. 3 is a left view of the internal-combustion engine.

FIG. 4 is a right view of the internal-combustion engine.

FIG. 5 is a top view of the internal-combustion engine; and

FIG. 6 is a perspective view of the internal-combustion engine.

The broken line showing portions of an engine is included for thepurpose of illustrating environmental structure and forms no part of theclaimed design.

The ornamental design for an internal-combustion engine, as shown anddescribed.